solve 5x-12y=-3 and 10x-4y=-25 by elimination
10 x - 24 y = -6
10 x - 4 y = -25
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0 x - 20 y = 19
y = -19/20 etc
so it ends up a fraction? and then i have to find x?
that is correct. If you dislike working with fractions, you can start over and eliminate y instead of x.
ok thank you
5 x - 12 y = - 3 Miltiply both sides by - 2
- 10 x + 24 y = 6
- 10 x + 24 y = 6
+
10 x - 4 y = - 25
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0 + 20 y = - 19
20 y = - 19 Multiply both sides by 20
y = - 19 / 20
10 x - 24 y = - 6
10 x - 24 * ( - 19 ) / 20 = - 6
10 x - ( 4 * 6 ) * ( - 19 ) / ( 4 * 5 ) = - 6
10 x - 6 * ( - 19 ) / 5 = - 6 Multiple both sides by 5
50 x - 6 * ( - 19 ) = - 30
50 x + 6 * 19 = - 30
50 x + 114 = - 30 Add 30 to both sides
50 x + 114 + 30 = - 30 + 30
50 x + 144 = 0 Subtract 144 to both sides
50 x + 144 - 144 = 0 - 144
50 x = - 144 Divide both sides by 50
x = - 144 / 50
x = 2 * ( - 72 ) / ( 2 * 25 )
x = - 72 / 25
The solutions are :
x = - 72 / 25
and
y = - 19 / 20
thank you
5x-12y=-3......times 2:
10x-4y=-25.......times 1:
10x-24y=-6:
10x-4y=-25:
0-20y=19:
y=-19/20....
subst. y into eqn. 2:
10x-4[19/20]=-25:
10x-76/20=-25:
200x-76/20=-25:
200x-76=500:
200x=576:
x=72/25 or 2.88.:
solutions are[x ,y: -19/20, 72/25 respectively]......by olambs{�6¥0�1ƒ5�1„0�1„9�1„5�1†9�6¥0}